Rotary engine.



A. E. GREENE. ROTARY ENGINE. APPLICATION FILED FEB. 26, 1909.

Patented Feb. 21,1911.

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A. E. GREENE. ROTARY ENGINE.. APPLICATION FILED FEB. 21?, 1909. 984,904. Patented Feb. 21, 1911.

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onerous.

AMBROSE EvEE'rs GREENE, .oE rUEBLo, coLoEAno.

ROTARY ENGINE.

Specification of Letters Patent.

Patented Feb; 21, 1911.

Application filed February 26, 1909. Serial No. 480,262.

To all whom it may concern:

' Be it known that I, AMBROSE E. GREENE, a citizen of the United States, residing at Pueblo, in the county of Pueblo and State of Colorado, have invented acertain new vand useful Improvement in Rotary E11- gines, of which the following isa full, clear,

concise,and exact description.

My invention relates to rotary engines, and its object is to provide an engine having increased efliciency, which is of simple and compact structure, and which can be manufactured at a-comparatively, low cost.

15 I Inately 'elliptical cross-section, a rotary My invention comprises a rotary engine havmg a cylinder of elliptical or approxishaft wliich is located eccentrically of the ellipse, on the minor axis thereof approximately at a point at which a chord equal in lengthto the minor axis and drawn perpendicularthere-to intersects said minor axis,

and a rotary pistonv blade having. a length equal to the length of the minor axis of the ellipse, said blade being slidably mounted on' said shaft to rotate therewith.

One feature of my invention relates to the particular construction of the piston blade and to the means by which it is slidably so cured to the rotary shaft.

A further feature of my invention relates to certain structural details whereby the invention is capable of being embodied in an' internal combustion engine.

These and other features of the invention may be ni'o'rercadily set forth in connection with the accompanying drawings, in which,

Figure 1 1s a front end elevation of a ;-gas-engine embodying my invention; Fig.

2.is'a vertical section of the engine shown in Fig; 1, said section being taken on theplane 'of the inner face of the cylinder head, so

as to show the interior construction of the engine; Fig. 3. is a central longitudinal vertical section ofthe engine; Fig. 4 1s a sec- .tion on the line -4=4 of Fig. 3; Fig. 5 is a diagrammatic view showing different posi-- tions assumed by the piston blade; and Fig.

'6 is a diagrammatic view illustrative of the advantage resulting from locating the r0- I taryshaft in accordance 'With'my invention.

. Similar reference characters designate similar parts throughout the several 'figures if The engine/is supported upon a suitable hollow cylinder 20f elliptical or. approximately elliptical cross section, the ends of which are closed by cylinder heads. 3, 3, clamped by bolts 4 to the'ends ofthe cylinder. A rotary shaft.5 extendslongitudina'lly through. the cylinder and has suitable bearings inthe cylinder headsv 3. Said shaft 5 is located eccentrically of: theellip" tical bore of the cylinder... By reference to Fig. 2, it will be noted that the shaft 5 lies in the. plane of the minor axis of the ellipse and at the point therein at which a chordof the ellipse equal in length to the minor axis and drawn perpendicular thereto intersects said minor axis.

Mounted to rotate wit-hthe shaft 5, but slidable transversely orradially thereof, is a rotary piston blade 6: Said piston blade has a length approximately equal to the length of the minor axis of the ellipse, and a width corresponding .to the length of the interior of the cylinder.- Since'the shaft is located in the cylinder in the position above described, it follows that when/the piston is in the horizontal position, as shown in Fig. 2, and also when in a vertical position, at right angles to the positi'onshown'in Fig.

2, it exactly fits the cylinder,t -he ends ofthe piston contacting with the curved. interior surface of the cylinder. Owingtothe particular location of'the axis of rotation of the piston blade the differencesin length of chords drawn through said axis .are re duced to a minimum. Take for example the ellipse shown in Fig.6, the ratio of whose major a?) to the minor axis 0d. is" ap proximately-ten to six, "in which theeccentricity of the ellipse is obviously considerable, and the two perpendicular chords drawn through the center 0 of the ellipse have a difference in length of over half the minor axis. a 1 I If a point p on the minor axis be located in the manner above described, that is so thatthe chord my, perpendicular to the axis cal at the point p is equal'to axisod, it will be found that none of the chords of'the ellipse drawn through such point p, as for example the chord wb, will have 'adifference in length of more than approximately one-sixth of the minoraxis. As the eccentricity of the ellipse decreases, this difference in length of chords drawn through said point still I I i further 0r example in an. 55 base 1,- ,The engine casing consi ts fi jel'lipse in which the major and minor axes 11o have a ratioaof to 9, such'as is approxiwmately the casein the elliptical cylinder extending through the axis of rotation of" the piston blade and also to take up any shown in Fig. 2, the differences in length of the chords drawn through the selected axis are so slight as to be almostneglig1ble. Hence by making the piston blade 6 .of a length equal to the length of the minor azns, said piston will approximately. fit said cylinder at every position of rotation of the piston blade.

In order to provide for any slight differences in' length of the chords of the ellipse wear of saidblade, each end of the piston blade is preferably provided with a spring:

pressed packing strlp '2'- forming the contactingend surface of the piston.

The piston 6 's preferably formed of two parallel plates 8, 8, spaced apartby blocks 9, 9 near each end thereof, said plates being clamped-against said spacing blocks by bolts 10.' A hollow rectangular openingor slot is thus left between the plates 8, 8, and the blocks 9,9, the width of said slot being suflicient to receive the shaft 5 and its length being sufficient to permit such-reciprocation ofthe piston,6, as it rotates, that the packing strips 7, 7, always 'remain in contact withthe inner surface of the cylinder 2.

. The spaced apart ends of the plates 8, 8

form sockets at the outer sides of the blocks 9,

a desirable contour to that end of-the piston blade which it is. desired shall receive the full effect of any motive fluid that may be employed to rotate said blade.

Each .of the plates 8, 8, is preferably in the form of a channel-iron, that is they are provided with flanges 12, 12 at the sides thereof, which engagewith the cylinder heads 3, as shown most clearly in Figs. 2 and 3. Said flanges have longitudinal grooves formed therein adapted toreceive spring pressed packing strips 13, which are thus pressed into intimate engagement with the cylinder head and insure a tight, but elastic fit between the sides of the piston and the cylin-.

der heads.

Two pins 14, 14: project diametrically through the shaft 5, preferably at points near the ends of the cylinder, and the projecting ends of said pins form bearings for cylindrical rollers 15, 15. The" piston'6 is thus rotatably secured to the shaft 5, while at the same time the rollers 15 facilitate the" sliding or reciprocation of the piston. The cylinder is provided with an inlet port 16- and' an outlet or exhaust port 17,

situated upon opposite sides of the shaft 5, and preferably so located thatas soon as one end of the piston in its rotation passes the exhaust port the opposite end of the piston willhave passed 'the inlet port, as indicated .in dotted lines in Fig. 2.

' The-usual fly-wheel 18 may be carried by the shaft 5 for reasons Well understood.

The structure thus far specifically described sets forth the preferred embodiment I of my invention whatever he the use to which the engine is put. For example, the invention may be embodied in a pump for pumping air, water, or other fiuids,'or in a steam engine, or in'an internal combustion engine, and the additions which may be necessary in order to adapt the invention to. the intended use will in general be well under stood by one skilled in the art.

clockwise, or in the direction indicated by. the arrows in Figs. 2 and 5. Assume further that the space below the piston, when the piston is in the position indicated by full lines in Fig. 5, is filled with a fluid. It

1 is obvious that as the piston rotates, and at the same time reciprocates on the shaft 5, as indicatedindotted lines in Fig. 5, the space to be occupied by said fluid decreases in volume and said fluid is either compressed, or, in case the exhaust port is open, is forced through the exhaust port. By the time the end of the piston has made a half-revolution and has again assumed the position shown in full lines in Fig. 5, though with its ends reversed, the fluid has been for the most part forced through the exhaust port 17, or, in case said port has been closed, is compressed in the spaceabove the piston. Meanwhile -the iston in its rotation 'has sucked in a fres supply of fluid through the inlet port 16, which fresh supply of fluid now occupies the space below the piston. From the foregoing description it is obvious howthe piston. during its rotation sucks in fluid on one side of the piston through the inlet port and tends to compress on its opposite side-or to force through the outlet port the fluid previously drawn into the cylinder.

From the foregoing description, it is believedthe adaptation of my invention to use as a pump is obvious and needs no further description. Hence in the drawingsI have shown an embodiment of the invention which is not so obvious, and will now de scribe certain parts which cooperate with those previously described to render-my in vention particularly adapted to use as an internal combustion engine.

, Assume that the piston is rotating counter The exhaust port 17 is controlled by a spring seated valve 19, which is adapted to be held open at predetermined periods by a bell-crank lever or tappet arm 20, pivoted at 21 upon a suitable support carried by the engine. The upper end of the tappet arm extends over the end of the valve rod 22.

The lower end of said tappet arm is provided with a roller 23 which rides over a cam wheel 24, carried upon the shaft of a gear wheel 25, which meshes with a similar gear wheel 26 secured upon the shaft 5. The teeth upon the intermeshing wheels 25 and 26 are such that a two to one gear is provided, that is the gear 25 and its cam wheel 24 make one revolution for each two revolutions of the shaft 5 and gear 26. The cam has a depression extending over onehalf of its periphery and hence is so shaped that during one half of its own revolution, or one complete revolution of the piston blade, it maintains the tappetarm 20 in position to hold open the valve 19. During the other half-revolution of the cam and the second complete revolution of the piston blade the tappet arm is held in position to permit the closure of said valve 19.

The inlet port 16 may be controlled by a lows: Assume that the piston is in the position shown by dotted lines in Fig. 2 with a compressed charge above the piston and -.fresh or uncompressed charge below the same. In such position of the piston, the arm of the piston extending to the left,in Fig. 2, from the shaft 5 is longer than the opposite arm. Beginning with the conditions above assumed acomplete cycle of operations of the engine occupies four halfrevolutions of the piston. These four portions of the cycle may be described as follows:

(1..) The spark plug is so timed that the charge is exploded at the moment the conditions assumed have occurred. The greater I force of the expansive power of the exthe arrows.

ploded gases is exerted, of course, upon the longer arm of the piston and hence the piston is, propelled in the direction indicated by During the first half-revolution of the piston the cam 24 is turned so that the valve '19 is closed. Hence the fresh charge is compressed into the space at the :topot the cylinder.

(2.) At the beginning of .the second half revolution the piston extends in its initial direction across the cylinder, but with its ends reversed. During the first half-revolution the pressure of the exploded gases held the inlet valve 27- closed, and hence the space below the piston is now occupied solely by spent gases. The cam 24 has now turned so that the valve 19 is open and will remain open during the second half-revolution of the piston. The compressed charge is now exploded and during this second half-revolution the previously exploded gases 7are exhausted through the exhaust port 1 V (3.) At the beginning of thethirdhalfrevolution, the space below the pistonfis; filled with spent gases resulting from "the previous explosion, but there is, of course, no compressed charge above the piston. During this third half-revolution of the pisten the suction created by the piston draws in a fresh charge behind the same, and meanwhile, the exhaust port being held open by the cam 24, the gases from the last explosion are exhausted. t

(4.) At the beginning of the fourth haltrevolution there is an uncompressed charge below the piston but no charge above the same. During this half-revolution the cam 24 is turnedso as to hold the'val've 19 closed, and hence during this last half-revolution of the cycle of operations, one charge of gas is being compressed upon one side of the pistonand another charge is being drawn in on the other side. At the end of the fourth half-revolution there is, therefore, a compressed charge above the piston and an uncompressed charge below-the same, the conditions assumed at thebeginning of' thecycle. 1

It will be observedtherefore, that a gas engine embodying my invention has a cycle comprising four half-revolutions .or strokes of the piston; During the first half revolution there is an explosion on one side of the piston and compression on the other s de;

during the second half-revolution there is explosion and exhaust, during the third half-revolution, suction and exhaust; and

during the fourth half-revolution suctio:n

and compression. It furthermore appears, in the operation of the gas-engme shown and described, that the cam 24 is-s'o rotated.

that during one complete revolution of the piston-blade the valve 19, which controls the exhaust port, is: in a closed position and. during the succeeding complete revolution of the piston blade said valve is in an open position, such open and closed ,posit on of the valve... alternating for each complete revolution of the piston-blade;

j. I claim:

1. In a rotary engine,the oinbination with an engine cylinder'comprising a hollowshe'll of elliptical cross-section and cylinder heads thereof.

secured to the ends of said shell, of a rotary shaft havingbearings in said cylinder heads,-

said shaft being located eccentrically of said cylinder 1n a line in which a chord equal in length to the minor axis and drawn perpendicular thereto intersects said minor axis, and a plston-blade having a length approximaitely equal to the length of the minor axis piston bladecarried by said shaft and mounted to reciprocate transversely thereof,

said piston-blade comprising two platesspaced apart to provide a slot extending longitudinally 'of the blade for receiving said shaft, and a spring pressed packing strip projecting-from each end of said blade.

3. Ina rotary engine, a rotary pistonblade comprising two plates, spacing blocks secured between said plates near each end thereof, thereby providing a longitudinally extending slot between said plates intermediate said blocks and also providing sockets at each end of the blade, packing strips mounted in said end sockets, andcu'shioning means interposed between said packing strips and said spacing blocks.

4. In a rotary engine, a rotary piston blade comprising two plates in the form of channel irons, the flanges ofsaid channel irons being provided with longitudinally extending 'groo-ves, spacing blocks secured be tween said plates near each end thereof, thereby providing a longitudinally extending slot between said plates intermediate said blocks and also providing sockets at each end of the blade, and packing strips mounted in said end sockets and in the grooves of said flanges.

5. In a rotary engine, the combination with a cylinder; of a rotary shaft located eccentrically of said cylinder; a rotary piston blade comprising two plates, spacing secured between said plates near each end thereof, thereby providing a longitudinally extending slot between said blocks for rece1v1ng said shaft and also providing a socket at each end of the blade, and packing strips mounted in said sockets; and means provided on said shaft'and piston blade and for'permitting a reciprocating'movement of said blade on said shaft.

6. Ina rotary engine, the combination with a cylinder, of a rotary shaft located eccentrica'lly of said cylinder, a piston-blade having a longitudinal slot for receiving said shaft and for permitting a transversggrec pp rocation of said blade on said shaft',"'and a I blocks pair of cylindrical rollers mounted upon op- I posite sides of said shaft within said slot.

7. In a rotary engine, the combination with an engine cylinder comprising a hollow shell of elliptical cross-section and cyl inder heads secured to the ends of said shell; of a rotary shaft having hearings in said cylinder heads, said shaft being located eccentrically of said cylinder in a line in which a chord equal in length to the minor axis and drawn perpendicular-thereto intersects said minor axis; a rotary piston blade comprising two plates, spacing blocksse cured between said plates, near ,each end thereof, thereby providing a longitudinally extending slot between said blocksfor re ceiving .said shaft and also providing a 7 socket at each end of the blade, and packing strips, mounted in said sockets; and a pair of cylindrical rollersmounted upon opposite sides of said shaft within said slot, whereby said piston blade is mounted to rotate. with said shaft and also to reciprocate transversely thereof.

8. In an internal combustion engine, the

combination with a. cylinder having an inlet and an exhaust portand valves for-controlling said ports, of a rotary shaft located eccentrically of said cylinder, a rotary pistonblade carried by said shaft and mounted to reciprocate transversely thereof, and means for maintaining the valve which controls the exhaust port alternately in a closed position for one complete revolution of the pistonblade and in an open position for a succeeding complete revolution thereof.

9. In an internal combustion engine, the combination with a cylinder having an inlet.

and an exhaust port and valves for controlling said ports, of a rotary shaft located eccentrically of said cylinder, a rotary piston- 2 blade carried by said-shaft and mounted to reciprocate transversely thereof, a two-toone gear operated fromsaid rotary shaft, a rotary cam carried by said gear, said cam having a depression extending over one-half I of its periphery and a bell-crank lever hav: ing one of its ends in engagement with said cam and the oth r end in position to control the operation of the valve of said exhaust ort. p 10. In an internal combustion engine, the combination with a cylinder having aninlet and an exhaust port and valves for controlling said ports, of a rotary shaft located eccentrically of said cylinder, a rotary pistonblade carried bysaid shaft and mounted to reciprocate transversely thereof, and means for controlling said valves so as to provide for a cycle of operations covering four half revolutions of the piston-blade and comprising' an explosion'of'gasesonone side of said iston and a compression of a charge on the other .side thereof during one-half revolu-' tion, an explosion andan exhaust during the y In witness whereofll hereunto subscribe succeeding half-revolution, the mimission of my name this 23rd day of Febru ary, A. D. 0 a fresh charge and the exhaust of the pre- 1909.

vibusly exploded chargeduring the succeed- 5- 'ing halfreveliltion, and the admission of a AMBROSE EVERTS GREENE fresh charge and the compression of the Witnesses:

previouslyeadmitted charge during the fieial GEORGE E. FOLK, half-revolution of the cycle' ALFRED H. MOORE. 

